Tongue-twisters in many languages, including Latin, but not Greek: http://www.uebersetzung.at/twister/index.htm
Oh… there is Greek, but I have no idea whether it is Classical or Modern or if they even distinguished between the two.
Oi! Where is my brain?! It must be Old Greek because there was a quote by Demosthenes.
Number 7(Latin) is the famous “Tete roro mama nunu dada tete lala tete.”
Which language is that for Mingshey?
I like this one in English: "I wish to wish the wish you wish to wish, but if you wish the wish the witch wishes, I won’t wish the wish you wish to wish. "
That will test your fluency (and memory) 
[quote author=benissimus link=board=16;threadid=638;start=0#5998 date=1063542191]
Oi! Where is my brain?! It must be Old Greek because there was a quote by Demonsthenes.
[/quote]
I see some modern phonemes and prepositions. So classical and modern greek are mixed with no distinction there, I would say.
Number 26(Greek ) sounds like this in modern pronunciation:
i spani ispani is pani ispaniko, is paniko ispaniko ezografoon.
Neat site! I love tongue twisters…I did pretty well on the wish to wish one, but some of the others are HARD! ;D
Keesa
Some of the evil ones are designed to make you swear. My great-grandmother taught me this one:
I slit a sheet
A sheet I slit
Upon a slitted sheet I sit
Say it three times
But don’t say it three times fast out loud! 
Keesa